Brought up in a farming family in Fife, he crossed the Border at 18 and only returned after 17 years in the City of London.
After seven years at fast-growing Rathbones in Edinburgh, he was headhunted this year to set up new offices in both Edinburgh and Newcastle for Psigma, the asset management arm of actuarial consultancy Punter Southall, which has 30 people in Edinburgh and 55 in Newcastle.
Now he is jostling with the likes of Rathbones, Murray Asset Management and Adam and Co for the bespoke investment mandates handed out by those with a spare £250,000 or more.
Living at St Boswells in the Borders with his wife and three children aged six to 10, the 45-year-old says: "It is quite reassuring because it is community-based … everyone knows everyone and you are meeting people, not just in silos."
He adds: "When you come from London, you think London is the core of the world, but coming up to Edinburgh and getting involved in the investment community is fascinating - they are very passionate about it, and you have the access to people you could never get in London - you are meeting them socially too which you could never do in London. It's a great place to do business."
Could a Yes vote threaten that? "It will create disruption … but that creates opportunity as well. We are committed to being up here, Scotland has got a lot to offer, and it could do a lot more to attract international business."
Trained at James Capel in the 1990s when the firm's teams of analysts bestrode the City, Mr Wishart learned the old-fashioned disciplines of company analysis.
"You have to have someone pulling the levers who understands the companies but who also understands the client," he says. "Some companies probably create what looks like a more bespoke opportunity but it might be a sausage factory underneath.
"If you were brought up analysing balance sheets and getting to know companies, you hopefully have a better understanding of something that invests in those things. That is going to be increasingly important in the future - because you have to understand which companies are exposed to rising interest rates."
Mr Wishart says managers in boutique structures, using a multi-asset approach, can for instance pick up smaller debt issues which are off-limits to big companies who need to invest £1 billion at a time. Convertibles, where investors buy bonds with rights to future equity at a fixed price, are about to make a comeback too, he says. "You have to be quite small and nimble, and thinking hard about it, otherwise you might end up in index-linked bonds of various sorts which look expensive because there is a lot of money chasing that."
Among his favourite equity managers are Edinburgh's David Gait (First State) and Harry Nimmo (Standard Life Investments). "We are huge fans of Harry … I think we are very spoilt up here, we have Baillie Gifford, a fantastic investment house, and Standard Life have been doing well. They think a lot harder than a lot of large institutions."
Rathbones grew their managed assets sixfold to £25 billion during Mr Wishart's total of 12 years with the firm, helped by acquiring a chunky business from Lloyds.
PSigma, from a standing start 12 years ago, is now at over £2bn. "You have to be a certain size to make things work, with the changing regulatory picture," Mr Wishart says. "PSigma is keen to build up a company that is not part of a big bank culture, which is more about protecting their risk than the risks of clients … Our model is to build up inflation-plus returns, focusing on making real money."
PSigma uses independent consultancy ARC to risk-rate its portfolios and report their performance.
"You have to be able to demonstrate you have thought really hard about all these things for your client, and if you haven't done that the regulator will rap your knuckles."
RBS-owned private bank Coutts this month announced a suitability review of all investments sold to its clients before November 2012, after discussions with the regulator.
Boutique player PSigma is now hunting corporate pension funds. "A lot of companies won't take on a pension fund unless it has more than £100 million," Mr Wishart says. "We regard even a small fund of £2m as a jolly good client. We think between £2m and £100m is a really interesting area."
Personal pensions have suddenly become more attractive since being liberated - for over-55s - by the Budget, the manager notes. "At the moment everyone is getting into property which is completely unproductive. We want it going into businesses and creating job opportunities.
"If this [reform] encourages greater interest in the investment world and more capital to be invested it must be good for the economy … rather than people saying my pension is my house."
The drive for more investment transparency is also threatening the business model of the industry, Mr Wishart observes. "Cost is an emotive subject. Big companies with historic revenue streams are probably rather reluctant to address it as quickly as they should - and probably aren't under real pressure to do so. If we as an industry can make it easier for people to understand and the costs simpler, hopefully it will become more accessible for people to engage with it."
Total expense ratios (TERs), creating a level playing field, are hugely important, the manager says, as is clarity about exit fees.
At Lloyds-owned St James Place, he notes, leaving the firm after one year would cost a client six per cent of his capital (then a sliding scale) - Psigma has no exit fees.
The advances in transparency and technology mean investors now have a right to expect clear, real-time platform information on the exact nature and value of their holdings, including past pensions, Mr Wishart says.
It may also drive bigger caches of money out into the open, he suggests. "There are monies which have been hidden in massive estates and haven't seen the light of day for generations, which may become accessible and accountable."
All disruption benefits smaller players, he says: "There is a lot of change ahead and the bigger you are, the harder it is to change."